Such a feed-through can be used to prevent emission of electromagnetic waves, for example to avoid electromagnetic interference or the leakage of critical information from a network switch or server placed in a cabinet or enclosure. For the latter application, standards, usually referred to using the term “TEMPEST”, are established that require attenuation up to the order of 100 dB at frequencies up to 10 GHz at the feed-through.
One example of such a feed-through, for optical cables, is described in U.S. Pat. No. 7,793,415-B2, which shows a flat member with a number of openings. An enclosure can be fitted around each cable to form a tube, and this tube can be attached to the flat member at an opening thereof. The flat member is in turn attached to an opening of a cabinet or other enclosure. This structure reduces electromagnetic interference to a desired level up to a frequency that is determined by the length and the inner diameter of the tube formed by the enclosure.
One problem associated with such a feed-through is how to facilitate installation of, for example, optical cables in a cabinet or other enclosure where the feed-through is used.